He drew a triangle on the blackboard.

He was drawing a tridecagon shape.

This figure is an acute triangle.

He taught me how to calculate the area of an obtuse triangle.

Please calculate the area of this right-angled triangle.

In traditional cosmology, Kakuun is considered one of the triangles.

He bought a new leather jacket.

He proposed a new theory about cosmology.

Traditional Japanese food is healthy and delicious.

The Winter Triangle is a shape that connects the brightest stars in the night sky.